News Releases from Region 3

EPA issues final decision for Chevron cleanup for
a gasoline release on the D.C.- Maryland border

PHILADELPHIA (April 16, 2008) – The U.S. Environmental Protection Agency has issued its final decision describing the remedy for a gasoline release that occurred at a former Chevron service station located at 5801 Riggs Road, Chillum, Md., which impacted the adjacent community in the Washington D.C. neighborhood known as Lamond-Riggs Park. The gasoline release occurred in 1989 and reportedly migrated underground to the residential neighborhood in 2001

“EPA's final decision includes key ideas from our proposed plan presented to the community last fall. We have also modified the cleanup plans to be even more protective in response to significant comments from the community and D.C. environmental agencies," said Donald S. Welsh, mid-Atlantic regional administrator.

EPA's final decision for the Chevron cleanup includes three components that were included in the Statement of Basis that was presented to the community in fall 2007:

(1) Continued operation of the existing groundwater remediation system in Maryland;

(2) Expansion of the existing system by installing angle recovery wells under Eastern Avenue into the District. The additional wells will enhance cleanup of contaminated ground water resulting from the Chevron release. The drinking water for the area comes from a public water supply. As such, there is no known risk to the drinking water from the underground contamination;

(3) Installation of individual vapor mitigation systems in those homes located above the contaminated groundwater plume with measured vapor levels that exceed EPA’s remediation standards for indoor air established in the Statement of Basis

In response to comments, EPA has strengthened its plan by adding:

(1) Installation of an independent remediation system on the District-side of Eastern Avenue which uses an innovative recovery well design combining soil vapor extraction, recirculation groundwater pumping, and air sparging. Treatment takes place inside a large diameter well underground, minimizing both space requirements and disruption to the community.

(2) Installation of an oxygen curtain above Nicholson Street to speed the natural degradation of the groundwater plume. The area above Nicholson Street has a low oxygen level and injecting oxygen will accelerate the natural degradation of dissolved petroleum constituents. The oxygen curtain is a non-mechanical system operated by pressure. It requires little space and will generate minimal noise, so it should not be disruptive to the community except during construction.

Implementation of EPA’s final decision will begin after EPA issues Chevron an implementation order which is a legally binding agreement. EPA will attend a future community forum to outline its final decision and to discuss the next steps in the cleanup process.